For a secular godless age, there is one virtue we promulgate about ourselves at almost all opportunities: tolerance. Among the British values often celebrated by politicians is our capacity for tolerance. Schools are required to instil values of tolerance into millions of children; Muslims are told to be tolerant by David Cameron. Tolerance has become something of a founding mythology for western developed nations: our tolerance is regarded as a mark of our superiority over many less tolerant, less developed nations around the world. Our tolerance – in contrast to the intolerance of many of our ancestors – is evidence of the concept of historical progress.

Our ancestors may have ripped each other apart over small theological differences, they may have persecuted those with different sexual preferences or ethnic identity, but in this enlightened age, we tolerate diversity. It is the one virtue the state regularly exhorts us to demonstrate.

But far from being the kind of unequivocal virtue the politicians proclaim it to be, take a closer look and the word collapses under the weight of contradicting expectations. A closer look is exactly what Frank Furedi, a sociologist, offers in a new book On Tolerance, which will infuriate and delight in equal measure – and probably leave a lot of confusion in its wake.

The problem is that tolerance – understood in its classical liberal sense as a virtue essential to freedom – has been hijacked and bankrupted, argues Furedi. Dragged into the politicisation of identity, tolerance has become a form of "polite etiquette". Where once it was about the tolerance of individuals and their opinions, it has now been "redeployed to deal with group conflicts". Once it was about opening the mind to competing beliefs, now it is about one that affirms different groups. Along this slippery path, much of the original importance of tolerance has been distorted or lost.

Tolerance has segued into meanings of nonjudgmentalism, recognition, acceptance, even implicitly, affirmation and respect. It has frequently slipped into a vague indifference – "you do what you like" type attitude to the people you live amongst.

What has been lost is JS Mill's understanding that tolerance is crucial to freedom. That tolerance is about putting up with views and opinions you may deeply disagree with; tolerance does not require abdicating judgement, only the firm belief that it is in the cut and thrust of debate that there is the best chance of truth. Furedi is brilliant at skewering what he depicts as our lazy reluctance to judge, quoting Hannah Arendt to back him up. Judging is about using, to our best abilities our reasoning and empathy, to discriminate and discern; not bothering is a form of, literally, antisocial behaviour, a withdrawal from our responsibilities and obligations to other people.

There are no shortage of critics of this anaemic, bastardised version of tolerance. Tariq Ramadan, the Muslim thinker, loathes the contemporary rhetoric of tolerance as the "intellectual charity" of the powerful, part of the vocabulary of "cultural domination". He says it is grudging and patronising. A left critique argues that tolerance is a discourse of "depoliticisation". And the critiques from the right argue that tolerance has fatally weakened European identity; David Cameron even blamed the riots on tolerance. The right associates it with its twin evil, relativism.

Furedi is a famous contrarian – he takes on accepted wisdom and turns it on its head – and tolerance is the perfect subject for him. He knocks down the pieties and delusions of our age with neat elegance, but lands you up in very uncomfortable places. His argument is that in our enthusiasm for tolerance, we have actually become a deeply intolerant culture. We pass legislation to police hate speech, campaigners launch tirades of abuse on climate change deniers, New Atheists lambast religious believers. On all fronts, Furedi sees examples of a new intolerance – the very popularity of the phrase "zero-tolerance" indicates the problem.

This is not the intolerance of witchcraft trials or the inquisition, but in our smug complacency, we overlook today's manifestations of enforcing conformity and managing behaviour. Furedi has no time for the paternalistic nudge theories of Cass Sunstein, which he argues provide evidence of how the Anglo-American cultural elites have little respect for the moral capacity and autonomy of normal people. Yet again, elites are trying to control other people's lives: in the past they did it on religious grounds, now it's legitimised by "research" from behavioural economics, neuroscience and evolutionary psychology. The result is that the liberal idea of "protecting the private sphere" is under serious cultural and political pressure.

This isn't a book you can easily agree with and in a way that's the point. It's deliberately provocative. Tolerance needs new champions who will redefine and re-energise an overused and misused ideal.

But like any ideal, it cannot trump all other ideals all the time, so I part company with Furedi on how you manage the conflict between equality and tolerance, solidarity and freedom. Hate speech may still need to be banned in specific instances, I would argue. But Furedi is right that tolerance is not some sort of nonjudgemental indifference. That's a cop out. Tolerance can be a really tough, demanding ideal of allowing space for the uncomfortable, the disagreeable and the radically different.